Anti-bacteria agent made from shell, and methods for purifying and desalinating water and for washing agricultural products with use thereof

ABSTRACT

For providing an anti-bacteria which is made from a natural material, therefore harmless if it is absorbed in the human body, can be produced in mass production with low cost, and shows a high anti-bacteria effect, the anti-bacteria agent is obtained by heating a shell in an atmosphere of inactive gas and burning the shell under the temperature which finally reaches 700° C.-2,500° C.

This application is a divisional of application Ser. No. 09/515,226,filed Feb. 29, 2000 now U.S. Pat. No. 6,365,193, which application(s)are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an anti-bacteria agent which issuitable for protecting foods from contamination with bacteria, inprocessed foods manufacturing industry, in food restaurant industry, andat home, and for disinfecting, sterilizing or pasteurizing in medicalindustry and medical welfare industry, and relates to a method fordesalinating and purifying sea water and river water, and further to amethod for washing or cleaning with use of water purified thisanti-bacteria agent.

2. Description of Prior Art

Chemical compound(s) of chlorine was used as a general anti-bacteriaagent. However, it sometimes generated trihalomethane in a treatment ofwaste water and/or generated dioxin in an incinerating or burningtreatment. As examples of anti-bacteria agents, which have been used asa food additive in farming and fisheries or marine products industry,there are synthetic anti-bacteria agent, such as sulfamizin, carbadox,or the like, as medicines for animals. However they must be strictlycontrolled, in particular, in residual value thereof to be less than astandard value, from a view point of safety of foods.

Therefore, the anti-bacteria agents made from natural materials asingredients, rather than the anti-bacteria agents of chemicalcompound(s) mentioned above are required, in particular, in a field oftreating foods which has a possibility to be taken inside the human bodythrough a mouth. For example, a report “An Effect of Green Tea On O-157”was published by the group of Prof. TeLdakatsu Shimamura, the medicaldepartment of Showa University, and attracted attention of manyconsumers. After this publication, catechin of tea, though it wasconventionally used as a food additive, has come into wide use.

The catechin of tea, attracting attention as an anti-bacteria agent madefrom a natural material, must be extracted from green tea as aningredient, therefore is not suitable for mass production. Accordingly,a new anti-bacteria agent is required, which is made from a naturalmaterial as an ingredient, is harmless when absorbed in the human body,can be produced in mass production with low cost, and shows a furtherhigh anti-bacteria effect.

In particular, an anti-bacteria agent which is made from a naturalmaterial and is harmless when absorbed into the human body, isconsidered also to have an effect on purification of water. Hereinafter,there are listed examples or cases now in issues.

First, the desalination of sea water can be listed. In the countries ofthe Middle East, freshwater is obtained from sea water through a reversepermeable membrane method, a distillation method, a refrigeration methodor an electric dialysis method, etc., in general. When salt etc., isremoved from sea water in this manner, bacteria can easily propagate.Therefore an anti-bacteria agent of Cr group or Cl group, is added toprevent the propagation of bacteria. However, the agent of the Cr groupor Cl group is extremely harmful to the human body, and a danger ofproducing cancer cannot be denied.

Second, the purification of river water can be listed. In river waterinto which drainage by human life (organic matter) flows, the BOD valueis high, and it generates bad smell.

Third, washing or rinsing of agricultural products can be listed. Toagricultural products after a harvest, an insecticide sometimes adheres.As a result of this, after agricultural products are washed with asynthetic detergent, they are rinsed with water for general use (i.e.,water from a water supply or from rivers), in order to wash suchinsecticide away. However, since ordinary water is poor in anti-bacteriaeffect or power by itself, there is a possibility that bacteriapropagates on the surface of agricultural products until they reachgeneral consumers.

SUMMARY OF THE INVENTION

For dissolving the problems mentioned above, according to the claim 1 ofthe present invention, there is provided an anti-bacteria agent madefrom shell. An anti-bacteria agent, according to the present invention,is obtained by heating a shell in an atmosphere of inactive gas andburning the shell under the temperature which finally reaches 700°C.-2,500° C.

As shells, a surf clam is the most preferable, since it is recognized tohave sterilizing power against general bacteria. However it may be anyone of an oyster, a scallop, a clam, a turban shell and a snail, if itis burned. By burning, the shell itself comes to be porous, therefore acontacting area is increased, thereby remarkably improving sterilizingor disinfecting power.

In particular, a shell powder of a surf clam, by burning in anatmosphere of inactive gas, shows strong and continuous property ofanti-bacteria against germs or bacteria, such as Escherichia coli O-157or the like, even if it is added only a little bit. It is also a naturalmateriel which mainly contains calcium, therefore it is safe for thehuman body. In addition, in a case where it is disposed, it nevercontaminates air, water, or soil. It also brings an effect that shells,which were too much to be managed as waste conventionally, can beutilized effectively.

If the anti-bacteria agent mentioned above is crushed to have a maximumparticle diameter equal to or less than 100 μm and have a mean particlediameter from 1 μm to 50 μm, it can be easily dissolved into water (inparticular, into warm water), thereby enabling to further improve itsanti-bacterial effect.

The burned shells made from natural material or natural ingredient aredescribed in No. 218 of the list of the existing additives, which isdefined in the revised version of the Food Hygiene Act and the NutritionImprovement Act as burned calcium (which mainly contains calciumcompounds obtained by burning shells or the like). It is officiallyrecognized to be safe for the human body.

Accordingly, regarding the anti-bacteria agent according to the presentinvention, it is preferable to be used for protecting foods fromcontamination by germs or bacteria in food service or food restaurantindustry or at home, and for sterilization, pasteurization, ordisinfection in medical industry or medical welfare industry.

The anti-bacteria agent of the present invention, which is applied todesalination, is made be contact with freshwater obtained from sea waterby using any one of the reverse permeable membrane method, thedistillation method, the refrigeration method or the electric dialysismethod.

As a result of such structure, it is possible to remove or remarkablyreduce the amount of a disinfectant or germicide of the Cr group or Clgroup added to freshwater after obtained from sea water.

According to the present invention, which is applied to purification ofriver water, the above-mentioned anti-bacteria agent is filled into anet (including a case through which river water permeates), and the netis provided to be laid within a river.

The burned shells, in addition to the anti-bacteria function of itself,come to be porous, therefore bacteria which decomposes organic matterpropagates on the surface thereof, thereby promoting purification ofriver water. Further, if river water is increased in a degree of anacidity thereof, the burned shells are dissolved into river water, so asto maintain a pH value within the most suitable range.

According to the present invention, which is applied to washing ofagricultural products, agricultural products such as vegetables, fruitsor the like are rinsed with water contacted with the above-mentionedanti-bacteria agent after washed with synthetic detergent.

As a result of this structure, it is possible to suppress propagation ofgerms or bacteria on the surface of such agricultural products for along time period.

BRIEF DESCRIPTION OF THE DRAWING(S)

FIG. 1 is a block diagram showing desalination processes for obtainingfreshwater from sea water;

FIGS. 2 (A) and (B) show a view explaining a purification method ofriver water and a perspective view of a net which is provided to be laidon river floor respectively; and

FIGS. 3 (A) and (B) are views showing a condition of washingagricultural products and a condition of rinsing after the washing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

Hereinafter, embodiments according to the present invention will befully explained by referring to the attached drawings.

A surf clam, as an ingredient or raw material of the anti-bacteria agentaccording to the present invention, is a kind of bivalves, and it isdistributed in the seas around the middle part of the main island ofJapan and in the northern part of the Sea of Japan. This surf clam isserved or used as a canned food, or a frozen or fresh food; however theshell of this is not used effectively. Therefore, the cost for supplyingis low.

To manufacture the anti-bacteria agent of the present invention from thesurf clam, first, the shells of the surf clam are crushed. The shellsare dried, and thereafter, they are roughly crushed by means of a grindmill and so on, thereby adjusting to be equal to or less than 5 mm in amaximum diameter thereof.

Next, the crushed shells are entered into an autoclave equipped with astirrer, and burned under an inactive gas atmosphere while beingstirred. The inactive gas is preferably to be nitrogen gas. A method ofincreasing temperature is not in question; however the final temperaturereaches a range from 700° C. to 2,500° C., more preferably, 900° C.±50°C., and the temperature is maintained for three (3) minutes or longer.

If the final temperature is less than 700° C., it is difficult to obtainthe anti-bacterial property. If it exceeds 1,000° C., an active portionof the particle is broken or destroyed, therefore it is also impossibleto obtain the anti-bacterial property. In addition, if the burning timeis less than three (3) minutes, it is difficult to obtain theanti-bacterial property It does not matter if the burning time is long;however it is preferable to be from three (3) minutes to five (5)minutes from a view point of the cost.

Then, the burned shell particles are cooled under the inactiveatmosphere, and thereafter they are further finely crushed andclassified or divided to be equal to or less than 100 μm in a maximumparticle diameter, to be from 1 μm to 50 μm in a mean particle diameter,and more preferably to be powders within a range from 2 μm to 5 μm.

In a case where the maximum diameter of the particles exceeds 100 μm orthe mean diameter exceeds a range from 1 μm to 50 μm, they cannot bedissolved into drink water, and they are deposited or settled, thereforeit is impossible to show their function. In a case where the meanparticle diameter is less than 1 μm, they absorb moisture, so as to besolid. It is difficult to handle.

However, depending upon the condition of use, it is also possible to usethe burned shells without crushing. If they are crushed into minuteparticles, they can be dissolved into water. Therefore the effect islarge; however the effect disappears in a short time. To maintain theeffect for a long time, it is preferable that the burned shells are usedwithout crushing, or powders crushed into minute particles are mixedtogether with a binder, and thereafter are burned, thereby forming intoa predetermined form.

The anti-bacteria agent manufactured in the manner mentioned above iseffective to Esherichia coli, such as O-157 or the like, food poisoningbacteria, such as Staphylococcus aureus, Psedomonas aeruginosa,Eumycetes, salmonella, enteritis vibrio or the like, and virus.

As a concrete use of the anti-bacteria agent according to the presentinvention, it can be used as an additive into a food, such as a boiledfish paste (called kamaboko in Japan) or the like, drink water,hand-washing water, and dental materials, such as an artificial tooth orthe like. In addition, it can be used to be put into a pot for home useas anti-bacteria powders pack, or to disinfect drink water for disasteror emergency time. It can be used to be added into a sheet which is forcleaning and wiping, a paper diaper, a wall paper, or buildingmaterials, as an anti-bacteria function additive. As other methods foruse, the anti-bacteria agent itself can be made into a ceramic, orsterilizing apparatus or device can be produced with use of theanti-bacteria function thereof.

The anti-bacterial agent according to the present invention shows ahigher anti-bacteria property than that of tea catechin or oyster shell.Therefore, it is characterized that the anti-bacteria effect can beobtained with a little amount, and that the effect is maintained for along time. For example, an addition amount for drink water or for otherobjects to be disinfected is sufficient to be 0.025 weight % withrespect to the weight of drink water or other objects. An amount morethan this may be added depending upon the condition of use. Theanti-bacteria effect can be maintained for a long time, and it isconfirmed that the effect can be maintained more than 48 hours.

EXAMPLES

Manufacture of Anti-Bacteria Agent:

Shells of surf clams were dried, and thereafter pre-crushed into about 2mm-3 mm in size. 500 g thereof were put into an autoclave equipped witha stirrer, which was filled with nitrogen gas and had a capacity of 2liters. A temperature was started to be increased while the stirrer wasslowly operated. This was continued until the temperature reached 900°C. After the shells were burned for five (5) minutes at 900° C., theheating was stopped. Then, the shells were left for cooling within theflow of nitrogen gas until the inside of the autoclave turned back tothe room temperature.

After being left for cooling, the burned shell powders were taken outfrom the autoclave, and they were further crushed by means of a mortar.The particles being equal to or less than 50 μm were selected by aselector, thereby manufacturing the anti-bacteria agent according to thepresent invention.

The ingredient concentration of this anti-bacteria agent is shown on thefollowing Table 1 (by an analysis according to soil nutriment analyzingmethod made by Yamagata-ken Rikagaku-Bunseki (physics and chemistryanalysis) Center: Yama-Bun-Se No. 778).

TABLE 1 Measured Concentration (wet Minimum Value of Ingredient weight%) Dectection Magnesium 0.04 Phosphor Bronze 0.02 Potassium 0.07 calcium25. Manganese 0.01 Iron 0.07 Copper Not detected 0.01 Zinc Not detected0.01 Molybdenum Not detected 0.01

Charcoal of bamboo crushed and adjusted to be particles equal to or lessthan 50 μm, in the same manner as mentioned above, separately, was mixedwith the above-mentioned anti-bacteria agent made from surf clams at aweight ratio 1:1, thereby manufacturing the anti-bacteria agentaccording to another embodiment.

Further, in place of surf clams, shells of oysters was used to be burnedand crushed in the same manner as mentioned above, thereby manufacturingoyster shell powders.

Test Bacteria:

Three kinds, i.e., Esherichia coli ATCC 8739, Staphylococcus aureus ATCC6538, and Psedomonas aeruginosa ATCC 9027) were used, and cultured, on aculture medium, such as a DD checker for general bacteria of blood agarflat plate, under a culturing condition for 18 hours at 37° C.

Testing Method:

Each of the anti-bacteria agents manufactured was dissolved intodistilled water and adjusted to be at a predetermined concentration.Then each of the above-mentioned test bacteria was added to thedistilled water into which the anti-bacteria agent was dissolved, so asto be about 106 pieces/ml.

After each bacteria was added, it was well stirred and left still at theroom temperature. After a predetermined time, it was sampled to bemeasured on numbers (pieces/ml) of the cultured bacteria.

Example 1

With use of a distilled-water solution (1 weight %, 0.5 weight %, 0.1weight %, and 0.05 weight %) of the anti-bacteria agent made from surfclams and manufactured in the manner mentioned above, the disinfectingeffects were examined on each of Esherichia coli, Staphylococcus aureus,and Psedomonas aeruginosa. The result is shown in Table 2.

Example 2

In the same manner as in Example 1 mentioned above, except that themixed anti-bacteria agent between surf clams and bamboo charcoal (weightratio: 1:1) was used in place of the anti-bacteria agent made from surfclams, the disinfecting effects of the mixed anti-bacteria agent wereexamined. The result is also shown in Table 2.

Example 3

In the same manner as in Example 1 mentioned above, except that ananti-bacteria agent made from oyster shells was used in place of theanti-bacteria agent made from surf clams, the disinfecting effects ofthe anti-bacteria agent were examined. The result is also shown in Table2.

TABLE 2 Concentration Staphylococcus Psedomonas Examples of Anti-Esherichia coli aureus aeruginosa and bacteria Agent After 15 After 24After 15 After 48 After 15 After 24 Comparison (W %) minutes hoursminutes hours minutes hours Example 1 1% <20 <20 <2 <2 <2 <2 0.5% <20<20 — — — — 0.1% <20 <20 1.9 × 10² 60 <2 <2 0.05% <20 <20 — — — —Example 2 1% <20 <20 2.0 × 10² 80 <2 <2 0.5% <20 <20 — — — — 0.1% <20<20 2.0 × 10⁴ 2.0 × 10² <2 <2 0.05% 4.0 × 10³ <20 — — — — Comparison 1%<20 <20 40 2 <20 2 1 0.5% 6.4 × 10² <20 — — — — 0.1% 2.5 × 10³ 2.5 × 10⁶4.0 × 10⁵ 5.2 × 10⁵ 2.2 × 10² <1 0.05% 2.5 × 10⁵ 1.2 × 10⁵ — — — —Reference: 6.0 × 10⁵ 4.0 × 10⁵ 4.0 × 10⁵ 3.6 × 10⁵ 8.0 × 10⁵ 4.0 × 10⁶Distilled water

As is apparent from the test results shown in Table 2, the anti-bacteriaagent made from surf clams achieved a sufficient disinfecting effecteven in a low concentration thereof, i.e., 0.05%. The effect wasmaintained not only after 24 hours, but also after 48 hours. Withrespect to the oyster anti-bacteria agent, the effect can be obtained inthe concentration of 1%. Accordingly, it can be said that surf clam isthe most effective.

Example 4

The concentration of the distilled-water solution of the anti-bacteriaagent made from surf clams was decreased to be lower than in Example 1(i.e., 0.025 weight %, and 0.005 weight %), the disinfecting effectswere examined on each of Esherichia coli and Staphylococcus aureus. Theresult is shown in Table 3.

Example 5

In the same manner as in Example 4 mentioned above, except that theanti-bacteria agent made from oyster shells was used in place of theanti-bacteria agent made from surf clams, the disinfecting effects wereexamined. The result is also shown in Table 3.

TABLE 3 Staphylococcus Concentration Esherichia coli aureus of Anti-(2.0 × 10⁵) (2.0 × 10⁵) Examples and bacteria Agent After 1 After 24After 1 After 48 Reference (W %) hours hours hours hours Example 30.025% 4 <2 20 <2 — — — — 0.005% 1.6 × 4.0 × 2.4 × 2.0 × 10⁵ 10⁴ 10⁴ 10²— — — — Example for  0.05% — — 4.0 × <2 Reference 10² — — — — —  0.01% —— 4.8 × 6.0 × 10⁴ 10² — — — — —

From the test results in Table 3, it is apparent that the anti-bacteriaagent made from surf clams achieves a sufficient disinfecting effecteven in a further lower concentration thereof, i.e., 0.025%.

Next, the further test of the disinfecting effects is conducted on theanti-bacteria agent made from surf clams according to the presentinvention (surf clam calcium powder), calcium bicarbonate, scallopshells, clam shells, turban shells, snail shells or oyster shells inYamagata-ken Rikagaku-Bunseki (physics and chemistry analysis) Center.The results are shown in the following Tables 4 through 16.

TABLE 4 (Sample: Surf clam calcium power (Present Invention)) Number ofGeneral Group Number of bacteria (/ml), Esherichia coli, Standard agarculture desoxycol acid salt medium method culture medium method TestingLiquid   120.  0. (Miscellaneous drainage of hot spring containingsample 0.1% W/V, sampled after 10 minutes) Reference Liquid 11,000. 410.(Miscellaneous drainage of hot spring)

TABLE 5 (Sample: Calcium bicarbonate (Burned at 1,000° C.)) Number ofGeneral Group Number of bacteria (/ml), Esherichia coli, Standard agarculture desoxycol acid salt medium method culture medium method TestingLiquid (River    56.  0. water containing sample 0.1% W/V, sampled after10 minutes) Reference Liquid 17,000. 57. (River water)

TABLE 6 (Sample: Calcium bicarbonate (Not Burned)) Number of GeneralGroup Number of bacteria (/ml), Esherichia coli, Standard agar culturedesoxycol acid salt medium method culture medium method Testing Liquid(River 18,000. 26. water containing sample 0.1% W/V, sampled after 10minutes) Reference Liquid 17,000. 57. (River water)

TABLE 7 (Sample: Dried scallop) Number of General Group Number ofbacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium method culture medium method Testing Liquid (River   720. 0. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 8 (Sample: Non-burned scallop) Number of General Group Number ofbacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium method culture medium method Testing Liquid (River 4,100.62. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 9 (Sample: Dried Clam) Number of General Group Number of bacteria(/ml), Esherichia coli, Standard agar culture desoxycol acid salt mediummethod culture medium method Testing Liquid (River   630.  0. watercontaining sample 0.1% W/V, sampled after 10 minutes) Reference Liquid3,100. 56. (River water)

TABLE 10 (Sample: Non-burned Clam) Number of General Group Number ofbacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium culture culture medium method Testing Liquid (River 3,700.48. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 11 (Sample: Dried Turban shell) Number of General Group Number ofbacteria (/ml), Esherichia coli, Standard agar culture desoxycol acidsalt medium method culture medium method Testing Liquid (River   720. 0. water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 12 (Sample: Non-burned Turban shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid 3,700.54. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 13 (Sample: Dried Snail shell) Group Number Number of General ofEsherichia coli, bacteria (/ml), desoxycol acid Standard agar culturesalt culture medium method medium method Testing Liquid   650.  0.(River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 14 (Sample: Non-burned Snail shell) Group Number Number of Generalof Esherichia coli, bacteria (/ml), desoxycol acid Standard agar culturesalt culture medium method medium method Testing Liquid 3,600. 47.(River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3.100. 56. (River water)

TABLE 15 (Sample: Dried Oyster shell) Group Number Number of General ofEsherichia coli, bacteria (/ml), desoxycol acid Standard agar culturesalt culture medium method medium method Testing Liquid   620.  0.(River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

TABLE 16 (Sample: Non-burned Oyster shell) Group Number Number ofGeneral of Esherichia coli, bacteria (/ml), desoxycol acid Standard agarculture salt culture medium method medium method Testing Liquid 3,700.62. (River water containing sample 0.1% W/V, sampled after 10 minutes)Reference Liquid 3,100. 56. (River water)

From the above Tables 4 through 16, it is apparent that shell powders ofsurf clam were inferior to calcium bicarbonate in a disinfecting poweror effect; however they were superior to shell powders of other shells.Also, including other shells, it is apparent that a remarkabledifference occurs between the burned one and the unburned one in adisinfecting power or effect.

Hereinafter, explanation will be given on embodiments for obtainingfreshwater from sea water, for purifying river water, and for washingagricultural products, by referring to FIGS. 1 through 3.

FIG. 1 is a block diagram for obtaining freshwater from sea water.First, sea water is pumped up by means of a pump into a reservoir tank.

Next, at a lower side of the reservoir tank a separation tank isprovided, which is divided into the first side chamber and the secondside chamber through a reverse permeable membrane, and sea water withinthe reservoir tank is sent into the first side chamber through aconduit.

A pressure of water head acts on the sea water in the first sidechamber, and freshwater is permeated through the reverse permeablemembrane into the second side chamber, with being removed NaCl etc.therefrom.

The freshwater in the second side chamber permeates through a columnwhich is filled with the anti-bacteria agent which is obtained byburning shells, such as surf clams or the like, while it is disinfected.Finally, it is supplied to a desired positions or places.

FIG. 2 (A) shows a method for purifying river water, and FIG. 2 (B)shows a perspective view of a net to be provided or positioned on a bedof river. In this embodiment, burned shells of such as surf clams or thelike, are filled in the net, and the net is provided or positioned on abed of river.

In a case of this embodiment, from a view point of maintaining apurification effect for a long time, it is preferable that burned shellsare not crushed finely. Since the burned shells come to be porous, thespecific surface area thereof is large, therefore, bacteria whichdecomposes organic matters is easily propagated thereon. When riverwater comes to be high in the acidity thereof, contents of shells aredissolved into river water, thereby achieving an effect to keep pH ofriver water constant.

FIG. 3 (A) shows a condition of washing agricultural products, and FIG.3 (B) shows a rinsing condition after washing. In this embodiment,within a container filled with a synthetic detergent, a basket(s) inwhich agricultural products are received is (are) dipped. Next, thebasket is taken out therefrom, and water which is contacted with theburned shells mentioned above is sprinkled on the agricultural productsby means of a shower, thereby removing the synthetic detergent attachedto the surface of the agricultural products.

As is fully mentioned above, the anti-bacteria agent according to thepresent invention, is manufactured by burning shell powders of surfclams etc. in an atmosphere of inactive gas, and it shows a highdisinfecting effect or power.

In more detail, it shows a disinfecting effect upon Esherichia coli,such as O-157 or the like, food poisoning bacteria, such asStaphylococcus aureus, Psedomonas aeruginosa, Eumycetes, salmonella,enteritis vibrio or the like, and further virus, in a low concentrationthereof, and it maintains the disinfecting function for a long time.

Further, shell powders of surf clams etc. are a natural material, whichmainly contains calcium which is used also as an additives into foods,therefore it is possible to provide an anti-bacteria agent safe for thehuman body, and it does not contaminate air, waste water and soil, evenwhen it must be processed to be disposed.

Furthermore, with use of the anti-bacteria agent according to thepresent invention, shells of surf clams etc. can be used effectively fordesalination of sea water, purifying river water, or for washingagricultural products, etc., though they are conventionally embarrassingthings as a disposal.

What is claimed is:
 1. A washing method of agricultural products,comprising the following steps: washing agricultural products, includingvegetables and fruits, with a synthetic detergent; and rinsing saidagricultural products washed with water which is contacted with ananti-bacteria agent obtained by heating a surf clam in an atmosphere ofinactive gas and burning said surf clam at a temperature which finallyreaches 700° C.-2,500° C.
 2. A method as defined in claim 1, whereinsaid surf clam is crushed before or after burned.
 3. A method as definedin claim 1, wherein said surf clam after crushed has a maximum particlediameter equal to or less than 100 μm, and has a mean particle diameterfrom 1 μm to 50 μm.
 4. A method as defined in claim 1, wherein theanti-bacterial agent includes a powder obtained by crushing charcoal ofbamboo.
 5. A washing method of agricultural products, comprising thefollowing steps: washing agricultural products, including vegetables andfruits, with a synthetic detergent; and rinsing said agriculturalproducts washed with water which is contacted with an anti-bacteriaagent obtained by heating any one of a scallop, a clam, a turban shelland a snail in an atmosphere of inactive gas and burning said any one ofa scallop, a clam, a turban shell, and a snail in a temperature whichfinally reaches 700° C.-2,500° C.
 6. A method as defined in claim 5,wherein said any one of a scallop, a clam, a turban shell and a snail iscrushed before or after burned.
 7. A method as defined in claim 6,wherein said any one of a scallop, a clam, a turban shell and a snailafter crushed has a maximum particle diameter equal to or less than 100μm, and has a mean particle diameter from 1 μm to 50 μm.
 8. A method asdefined in claim 5, wherein the anti-bacterial agent includes a powderobtained by crushing charcoal of bamboo.